Insulating double-glazing unit and vacuum double-glazing unit

ABSTRACT

The present invention relates to a heat-insulating multiple glazing and a vacuum multiple glazing. Conventionally, this type of glass does not provide sufficient heat-insulating performance. And, it has been necessary to form the heat-insulating multiple glazing thick, in order to enhance the heat-insulating performance. The present invention comprises a first vacuum multiple glazing (2) including two sheet glasses (3), (4) having peripheries thereof sealed and a plurality of layers of spacer (5) disposed within a gap therebetween, with the gap being depressurized; and a second vacuum multiple glazing (2) or an ordinary sheet glass (10) overlapped with the first multiple glazing (2) with a gap relative thereto and having the periphery thereof sealed with a sealing material (12), with the gap being charged with dry air or rare gas. Thus, it is possible to enhance the heat-insulating performance, without increasing the thickness of the entire heat-insulating multiple glazing.

This application is a Section 371 of PCT/JP96/03172.

TECHNICAL FIELD

The present invention relates to a heat-insulating multiple glazing andvacuum multiple glazing for use in a building construction or the like.

BACKGROUND ART

For constructions such as a house or a building, there is a need forsaving energy consumption through improvement in the heating or coolingefficiency. As the efficiency of heating or cooling depends on theheat-insulating performance or air-tightness of the construction,heat-insulating wall materials and heat-insulating window glasses havebeen developed.

However, a heat-insulating window glass generally has a higherheat-through ratio than a heat-insulating wall material, hence a lowerinsulating performance. Accordingly, in order to achieve energyconsumption saving, it is necessary to enhance the heat-insulatingperformance of the heat-insulating window glass. As a heat-insulatingwindow glass having a higher heat-insulating performance, a multipleglazing is known. This multiple glazing is shown in FIG. 5.

FIG. 5 shows a cross-sectional construction of a conventionalheat-insulating multiple glazing. This heat-insulating multiple glazing100 includes two sheets of sheet glasses 101, 102 overlapped with eachother with spacers 103 interposed therebetween sealing the peripheriesof the plates and also with dry air being charged in the intermediategap. This heat-insulating multiple glazing may achieve a heat-insulatingperformance equivalent to a heat-through ratio of 3.0-4.0 kcal/m² hr° C.

On the other hand, the heat-insulating wall material provides aheat-through ratio of 1/10 (0.3-0.4 kcal/m² hr° C.) of that of theheat-insulating multiple glazing 100. Accordingly, enhancement of theheat-insulating performance of the heat-insulating multiple glazing maylead to energy consumption saving. Following measures (a)-(d) are knownfor enhancing the heat-insulating performance of the heat-insulatingmultiple glazing 100.

(a) Low-radiating films are formed on inner surfaces of the sheetglasses 101, 102 of the heat-insulating multiple glazing 100, so thatthe low-radiating films may reflect infrared beam, thereby improving theheat-insulating performance.

(b) The dry air charged between the sheet glasses 101, 102 is replacedby rare gas so as to restrict convection between the sheet glasses 101,102. As the rare gas, gas such as argon or krypton which hardly causesconvection is employed, so that the convection between the sheet glasses101, 102 may be appropriately restricted.

(c) The heat-insulating performance may be enhanced by increasing thenumber of the sheet glasses 101, 102 of the heat-insulating multipleglazing 100 or by increasing the gap between the sheet glasses 101, 102.

The heat-insulating performance may be enhanced by depressurizing thegap between the sheet glasses 101, 102 of the heat-insulating multipleglazing 100 thus restricting air convection.

However, in the case of (a), it is necessary for the low-radiating filmto have light-through property so as to allow introduction of light intothe indoor space. Then, in order to satisfy both of the low-radiatingproperty and the light-through property, it is necessary to restrict theheat-through ratio of the heat-insulating multiple glazing 100 to about1.0-1.5 kcal/m² hr° C. Hence, this value is still insufficient whencompared with the heat-through ratio: 0.3-0.4 kcal/m² hr° C. of theheat-insulating wall material.

In the case of (b), in combination with the low-radiating film, theheat-through ratio of the heat-insulating multiple glazing 100 may bereduced to 1.0 kcal/m² hr ° C. However, this is still insufficient whencompared with the heat-through property: 0.3-0.4 kcal/m² hr° C. of theheat-insulating wall material.

In the case of (c), the heat-through ratio of the heat-insulatingmultiple glazing 100 may be reduced to 0.5 kcal/m² hr° C. However, theincrease in the number of the sheet glasses 101, 102 will result inincrease in the thickness of the heat-insulating multiple glazing 100.Then, the cost of the window frame for use with the heat-insulatingmultiple glazing 100 will increase. Further, the increase in the numberof sheet glasses 101, 102 will result also in the cost of theheat-insulating multiple glazing 100.

In the case of (d), the heat-through ratio of the heat-insulatingmultiple glazing 100 may be reduced to 1.0 kcal/m² hr° C. approximately.Accordingly, if the low-radiating films are formed on theheat-insulating multiple glazing 100, it may be possible to reducesufficiently the heat-through ratio without inviting increase in thethickness of the heat-insulating multiple glazing 100.

However, in order to allow the heat-insulating multiple glazing 100 in abuilding construction, it is necessary to maintain the gap between thesheet glasses 101, 102 under the evacuated depressurized condition foran extended period of time; and the gap between the sheet glasses needsto be firmly sealed by a high-temperature treatment (above 400° C.) likethe welding.

Further, if the low-radiating film is formed on the surface of theheat-insulating multiple glazing, there is the risk of the low-radiatingfilm being damaged. So, it is preferred that the low-radiating film beformed on the inside of the heat-insulating multiple glazing.Accordingly, it becomes necessary to form the low-radiating film beforethe sealing of the peripheries of the two sheet glasses.

Incidentally, most of such low-radiating films are vulnerable to hightemperature, so that they cannot effectively resist the high temperatureused in the welding treatment for sealing the heat-insulating multipleglazing 100. A low-radiating film capable of effectively resisting thehigh temperature is known which is formed of tin oxide doped withfluorine formed by the thermal decomposition method. This provides aradiation ratio of 0.15. Therefore, if this low-radiating film is formedon the heat-insulating multiple glazing, the heat-through ratio of theheat-insulating multiple glazing 100 will hardly be reduced further from1.0 kcal/m² hr° C. Hence, the heat-through ratio of the heat-insulatingmultiple glazing 100 is still insufficient, when compared with theheat-through ratio of the heat-insulating wall material ranging between0.3-0.4 kcal/m² hr° C.

Then, in view of the above-described problems of the prior art, anobject of the present invention is to provide art capable of enhancingthe heat-insulating performance without increasing the thickness of theheat-insulating multiple.

SUMMARY OF THE INVENTION

The above-noted object is achieved by the invention set forth in theclaims.

First, a heat-insulating multiple glazing, according to thecharacterizing features of the present invention, comprises: a firstvacuum multiple glazing including two sheet glasses having peripheriesthereof sealed and a plurality of layers of spacer disposed within a gaptherebetween, with the gap being depressurized; and a second vacuummultiple glazing or an ordinary sheet glass overlapped with the firstmultiple glazing with a gap relative thereto and having the peripherythereof sealed with a sealing material, with the gap being charged withdry air or rare gas.

The heat-insulating multiple glazing employs at least one vacuummultiple glazing. This vacuum multiple glazing includes two sheetglasses disposed with a predetermined gap therebetween, which gap isdepressurized. The vacuum multiple glazing having the above constructionhas substantially same thickness as one ordinary sheet glass for use ina heat-insulating multiple glazing, yet provides a higher heat-insultingperformance. And, this vacuum multiple glazing, like one ordinary sheetglass, is assembled in the heat-insulating multiple glazing.

With the above, it has become possible to enhance the heat-insultingperformance without increasing the thickness of the heat-insulatingmultiple glazing.

Incidentally, as the rare gas, helium, neon, argon, krypton, xenon orthe like may be employed. However, it is preferred to employ argon,krypton, xenon or the like which hardly cause convection.

Further, according to the present invention, a low-radiating film havinga heat-through ratio not exceeding 1 kcal/m² hr° C. may be formed oneither one or both of an opposing inner face of the further vacuummultiple glazing or the ordinary sheet glass opposing the first vacuummultiple glazing and an opposing inner face of the first vacuum multipleglazing opposing the second vacuum multiple glazing or the ordinarysheet glass.

With this heat-insulating multiple glazing, dry air or rare gas ischarged between the vacuum multiple glazing and the other sheet glass.For this reason, it is possible to maintain the balance between theoutside and the inside of heat-insulating multiple glazing, so that theperipheries of the two sheet glasses may be sealed with elastic sealingmaterial. Therefore, there is no need for welding by a high-temperature(above 400° C.) treatment of the peripheries of the two sheet glasses,as is the case with the vacuum multiple glazing.

With the above, it is possible to form a low-radiating film having noheat resistance (having a radiating ratio of 0.15 or less and aheat-through ratio of 1.0 kcal/m² hr° C. or less) on the heat-insulatingmultiple glazing (i.e. at least one of the opposing inner face of thefurther vacuum multiple glazing or the ordinary sheet glass opposing tothe vacuum multiple glazing and the inner opposing face of the vacuummultiple glazing opposing to the further vacuum multiple glazing or theordinary sheet glass), so that the heat-insulating performance of theheat-insulating multiple glazing may be further improved.

Incidentally, the low-radiating film having heat resistance may beformed in advance on the opposing inner face of the vacuum multipleglazing. In this case, however, the following respects (i), (ii) need tobe considered.

(i) The low-radiating film must be limited to those which have aradiating ratio of 0.15 or lower and whose heat-through ratio hardlydrop any further from 1.0 kcal/m² hr° C.

(ii) If a forcible attempt is made to improve the heat-insulatingperformance of the vacuum multiple glazing by means of a low-radiatingfilm, there develops a temperature difference between the front side andthe rear side of the sheet glass. And, if the difference is significant,this may lead to breakage.

Furthermore, according to the characterizing features of a vacuummultiple glazing, the glazing comprises two sheet glasses with aplurality of spacers disposed in a gap therebetween and having theperipheries thereof sealed, the gap being depressurized by means ofevacuating or the like, wherein said each sheet glass has a thicknessnot exceeding 1.5 mm and the spacers are disposed with a pitch notexceeding 15 mm.

By reducing the disposing pitch of the spacers while forming thin thesheet glass which constitutes the vacuum multiple glazing, it ispossible to form the vacuum multiple glazing thin without breaking thesheet glasses. Accordingly, it has become possible to selectively adaptthe vacuum multiple glazing for a particular application.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a section view of a heat-insulating multiple glazing relatingto a first embodiment,

FIG. 2 is a section view of a heat-insulating multiple glazing relatingto a second embodiment,

FIG. 3 is a section view of a heat-insulating multiple glazing relatingto a third embodiment,

FIG. 4 is a plan view of the heat-insulating multiple glazing of FIG. 3,and

FIG. 5 is a section view of a conventional heat-insulating multipleglazing.

DETAILED DESCRIPTION

Modes of embodying the present invention will be described in detailswith reference to the accompanying drawings. Incidentally, the drawingsshould be viewed in the direction of the reference marks.

FIG. 1 shows a cross sectional construction of a heat-insulatingmultiple glazing relating to a first embodiment.

A heat-insulating multiple glazing 1 includes a vacuum multiple glazing2 having an overall thickness of t₁ and acting as a first vacuummultiple glazing, an ordinary (not a vacuum multiple glazing, but of anordinary type) sheet glass 10 overlapped with this vacuum multipleglazing 2 with a gap therebetween, and a sealing material 12 for sealingthe peripheries of the vacuum multiple glazing 2 and the ordinary sheetglass 10. Between the sheet glass 10 and the vacuum multiple glazing 2,there is charged dry air or rare gas.

The vacuum multiple glazing 2 includes two thin sheet glasses 3, 4having a thickness denoted by t₂ and disposed with a gap therebetween, aplurality of spacers 5 interposed between these two thin sheet glasses3, 4 and a solder glass 6 fused and sealingly fixed to the peripheriesof the two thin sheet glasses 3, 4 at a high temperature of 400-500° C.And, the glazing is placed under a depressurized condition by airpresent between the two thin sheet glasses 3, 4 being evacuated.

The ordinary sheet glass 10 has a thickness denoted with t₃ and on anopposing inner face thereof facing the vacuum multiple glazing 2, thereis formed a low-radiating film 11. This low-radiating film 11 reflectsinfrared beam thus reducing a heat-through ratio of the sheet glass 10,so that the heat-through ratio of the heat-insulating multiple glazingwill not exceed 1 kcal/m² hr° C.

The sealing material 12 consists e.g. of a primary sealing material 12aand a secondary sealing material 12b. The primary sealing material 12amay be formed preferably of isobutylene-isoprene rubber or the like, andthe secondary sealing material 12b may be formed preferably of sulphidesealant (or silicone sealant). These materials may be used at the normaltemperature.

Incidentally, the gap s₁ between the vacuum multiple glazing 2 and theordinary sheet glass 10 is preferably 6-20 mm. If the gas s₁ exceeds 20mm, there tends to occur convection of the dry air or rare gas chargedinto this gap s₁, thereby to reduce the heat-insulating performance. Ifthe gap s₁ is not greater than 6 mm, the layer of the dry air or raregas charged into this gap s₁ is too thin, thus being unable to enhancethe heat-insulating performance.

In the heat-insulating multiple glazing 1 according to the firstembodiment, there has been described the case where the low-radiatingfilm 11 is formed only on the opposing inner face of the ordinary sheetglass 10 facing the vacuum multiple glazing 2. Instead, the followingthree other arrangements are also possible.

(1) The low-radiating film 11 is formed on the opposing inner face ofthe ordinary sheet glass 10 opposing the vacuum multiple glazing 2. Inaddition, another low-radiating film 11 is formed on the opposing innerface of the thin sheet glass 4 constituting the vacuum multiple glazing2 opposing the ordinary sheet glass 10.

(2) Without forming the low-radiating film 11 on the opposing inner faceof the ordinary sheet glass 10 opposing the vacuum multiple glazing 2,the low-radiating film 11 is formed only on the opposing inner face ofthe thin sheet glass 4 constituting the vacuum multiple glazing 2opposing the ordinary sheet glass 10.

(3) The low-radiating film 11 is formed on neither of the opposing innerfaces of the ordinary sheet glass 10 and the thin sheet glass 4 of thevacuum multiple glazing 2.

Furthermore, in place of the ordinary transparent sheet glass 10, a wireglass or sheet glass rendered non-transparent may be employed.

Next, a cross-sectional construction of a heat-insulating multipleglazing relating to a second embodiment is shown in FIG. 2.

This heat-insulating multiple glazing 15 has an entire thickness t₄ andincludes two vacuum multiple glazings 2, 2 used as first and secondvacuum multiple glazings, and a sealing material 12 sealing theperipheries of these vacuum multiple glazings 2, 2. Between the twovacuum multiple glazings 2, 2, there is charged dry air or rare gas.

In this second embodiment, there has been described the heat-insulatingmultiple glazing 15 using the two vacuum multiple glazings 2, 2.Instead, the heat-insulating multiple glazing may be constituted of morethan three vacuum multiple glazings 2. However, although increase in thenumber of the vacuum multiple glazings 2 may reduce the heat-throughratio, this will also increase the thickness of the heat-insulatingmultiple glazing. Thus, an appropriate selection needs to be madedepending on the purpose of the use.

Incidentally, the vacuum multiple glazing 2 employed in the first andsecond embodiments (see FIG. 1, FIG. 2) has the thickness t₂ of about 6mm. The reason why the thickness t₂ is set at about 6 mm is as follows.In general, with the vacuum multiple glazing 2, it is necessary for thethin sheet glasses 3, 4 to have a thickness of at least 3 mmapproximately to ensure strength and also for the two thin sheet glasses3, 4 to have a gap of at least 0.2 mm to enhance the heat-insulatingperformance.

On the other hand, there is a demand to employ a vacuum multiple glazing2 thinner than 6 mm or a vacuum multiple glazing 2 of a lower cost.However, since the gap between these two thin sheet glasses 3, 4 of thevacuum multiple glazing 2 is depressurized, there will be a risk ofbreakage of the thin sheet glasses 3, 4 if the thin sheet glasses 3, 4have a thickness less than 3 mm.

Then, through repeated trial productions, the present inventors havestriven to find out appropriate conditions allowing manufacture of athin vacuum multiple glazing. The construction of this thin vacuummultiple glazing will be described next with reference to FIGS. 3, 4.

FIG. 3 shows a cross-sectional construction of a vacuum multiple glazingrelating to a third embodiment.

This vacuum multiple glazing 20 has a thickness denoted with t₆ andincludes two thin sheet glasses 21, 22 disposed with a gap therebetween,a plurality of spacers 23 interposed between the two thin sheet glasses21, 22 and a solder glass 24 for tightly sealing the peripheries betweenthe two thin sheet glasses 21, 22. Each of the two thin sheet glasses21, 22 is an ordinary glass; and the solder glass 24 is fused by a hightemperature (400-500° C.) for tightly sealing between the thin sheetglasses 21, 22. The thin sheet glasses 21, 22 have a thickness denotedwith t₅ and a gap between the two thin sheet glasses 21, 22 is denotedwith s₃. The gap between the two sheet glasses 21, 22 is depressurizedto 10⁻³ Torr or lower. With this, it is possible to restrict airconvection sufficiently. Accordingly, like the ordinary heat-insulatingmultiple glazing charged with dry air or rare gas, the heat-throughratio may be reduced reliably, without using any thick air layer.

FIG. 4 shows the construction in plan view of the vacuum multipleglazing relating to the third embodiment.

In the vacuum multiple glazing 20, between the two thin sheet glasses21, 22 (only the numeral 21 is shown), there are interposed a pluralityof spacers 23. These spacers 23 are stainless steel column membershaving a diameter d and are arranged on a grating having a disposingpitch p. In FIG. 4, the plurality of spacers 23 are arranged along adiagonal grating pattern relative to the sheet glass. However, theinvention is not limited to this arrangement, and the spacers may bearranged along an ordinary grating pattern, i.e. a grating patternparallel with the peripheries of the sheet glass.

In this construction, by forming the thickness t₅ of the thin plateglasses 21, 22 thin (see FIG. 3) and also reducing the disposing pitch pof the spacers 23, breakage of the thin sheet glasses 21, 22 may beavoided. Specifically, this may be done by providing each sheet glasswith a thickness not exceeding 1.5 mm and setting the disposing pitch ofthe spacers at a value not exceeding 15 mm. With these, it has becomepossible to manufacture the vacuum multiple glazing 20 having thereduced thickness t₆ (see FIG. 3).

In this third embodiment, there has been described the vacuum multipleglazing 20 employing the spacers 23 formed of stainless steel. Insteadof this, spacers formed of glass or ceramics may be employed.

Since glass has a low heat transfer coefficient, increase of theheat-through ratio may be restricted even if the number of the spacersis increased. Further, as glass has a superior light transmissionproperty, the increase in the number of the spacers will not deterioratethe appearance.

In addition, a low-radiating film may be formed on at least one of thesurfaces of the thin sheet glasses 21, 22 constituting the vacuummultiple glazing 20. By forming the low-radiating film on the face ofthe thin sheet glass 21, 22 after forming the vacuum multiple glazing20, it is possible to form the low-radiating film vulnerable to a hightemperature. Needless to say, a low-radiating film having a reflectingratio no greater than 0.15 and resistance against high temperature maybe formed before the formation of the vacuum multiple glazing 20.

Incidentally, the vacuum multiple glazing 20 may solely be used in awindowpane or the like, or may be used in the heat-insulating multipleglazings 1, 15 shown in FIGS. 1 and 2, respectively. Namely, thisglazing may be employed in place of the vacuum multiple glazing 2 of theheat-insulating multiple glazings shown in FIG. 1 and FIG. 2. With theabove, it becomes advantageously possible to obtain a heat-insulatingmultiple glazing without increasing the entire thickness thereof.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Next, the first embodiment relating to the present invention will bedescribed with reference to Table 1.

                  TABLE 1                                                         ______________________________________                                        sheet glass  thickness (t.sub.3)                                                                        6.0 mm                                                         low-radiating film                                                 vacuum       thickness (t.sub.2)                                                                        6.0 mm                                              multiple glazing                                                                           heat-through ratio                                                                         1.0 kcal/m.sub.2 hr° C.                      gap          S.sub.1      15.0 mm                                                          charged gas  dry air                                             sealing      double sealing with isobutylene-isoprene                                      rubber and sulfide sealant                                       heat-insulating                                                                            thickness (t.sub.1)                                                                        27.0 mm                                             multiple glazing                                                                           heat-through ratio                                                                         about 0.7 kcal/m.sup.2 hr° C.                ______________________________________                                    

The vacuum multiple glazing 2 shown in FIG. 1 has the thickness t₂ of6.0 mm and a heat-through ratio of about 1.0 kcal/m² hr° C. The ordinarysheet glass 10 has the thickness t₃ of 6.0 mm, and has the low-radiatingfilm 11 formed on the inner face thereof. The gap S₁ between the vacuummultiple glazing 2 and the ordinary sheet glass 10 is 15 mm, and theperipheries between the vacuum multiple glazing 2 and the ordinary sheetglass 10 was double-sealed with isobutylene-isoprene rubber and sulfidesealant. And, between these, dry air was charged. The heat-insulatingglass 1 manufactured under the above conditions had a thickness t₁ of27.0 mm and a heat-through ratio of about 0.7kcal/m² hr° C., which valueis smaller than the target value of 1.0 kcal/m² hr° C.

Next, the second embodiment relating to the present invention will bedescribed with reference to Table 2.

                  TABLE 2                                                         ______________________________________                                        vacuum       thickness (t.sub.2)                                                                        6.0 mm                                              multiple glazing                                                                           heat-through ratio                                                                         1.0 kcal/m.sup.2 hr° C.                                 low-radiating film                                                 gap          S.sub.1      15.0 mm                                                          charged gas  rare gas                                            sealing      double sealing with isobutylene-isoprene                                      rubber and sulfide sealant                                       heat-insulating                                                                            thickness (t.sub.4)                                                                        27.0 mm                                             multiple glazing                                                                           heat-through ratio                                                                         about 0.37 kcal/m.sup.2 hr° C.               ______________________________________                                    

The vacuum multiple glazings 2, 2 shown in FIG. 2 has the thickness t₂of 6.0 mm and a heat-through ratio of about 1.0 kcal/m² hr° C. Thelow-radiating films 11, 11 are formed respectively on the opposing innerfaces of the two vacuum multiple glazings 2, 2 opposed to each other.The gap S₂ between the two vacuum multiple glazings 2, 2 is 15 mm, andthe peripheries between these was double-sealed withisobutylene-isoprene rubber and sulfide sealant. And, into this gap,rare gas was charged. The heat-insulating glass 15 manufactured underthe above conditions had a thickness t₄ of 27.00 mm and a heat-throughratio of about 0.37kcal/m² hr° C., which value is smaller than thetarget value of 1.0 kcal/m² hr° C.

Next, the third embodiment relating to the present invention will bedescribed with reference to Table 3.

                  TABLE 3                                                         ______________________________________                                        thin sheet glass                                                                        thickness (t.sub.5)                                                                          1.5 mm                                               gap       S.sub.3        0.2 mm                                                         depressurized  10.sup.-3 Torr                                       sealing   fused sealing with low melting-point glass                          spacers   diameter (d)   0.5 mm                                                         height         0.2 mm                                                         material       stainless steel                                                disposing pitch                                                                              arranged on grating                                                           pattern with disposing                                                        pitch of 15 mm                                       vacuum multiple                                                                         thickness (t.sub.6)                                                                          3.2 mm                                               glazing   heat-through ratio                                                                           about 2.55 kcal/m.sup.2 hr° C.                          sound-proof performance                                                                      equivalent to JIS sound-                                                      proof performance Class 25                           ______________________________________                                    

The thin sheet glasses 21, 22 shown in FIG. 3 had the peripheriesthereof fuse-sealed with low melting-point glass and has a thickness t₅of 1.5 mm and a gap S₃ of 0.2 mm. And, this gap S₃ was depressurized tobe lower than 10⁻³ Torr.

The spacer 23 is a stainless piece having a diameter d of 0.5 mm, andthese spacers were arranged on a diagonal grating pattern with adisposing pitch p of 15 mm. The spacer 23 has a height of 0.2 mm.

The vacuum multiple glazing 20 manufactured under the above conditionshad a thickness t₆ of 3.2 mm and a heat-through ratio of about 2.55kcal/m² hr° C., which thickness t₆ is about 1/2 of that of theconvention.

Incidentally, as for the sound-proof performance, a value equivalent toJIS (Japanese Industrial Standards) sound-proof performance Class 25 wasachieved.

We claim:
 1. A heat-insulating multiple glazing comprising:a firstvacuum multiple glazing including two sheets of glass having peripheriesthereof sealed and a plurality of spacers disposed within a gaptherebetween, the gap being depressurized; a second vacuum multipleglazing or an ordinary sheet glass, said second vacuum multiple glazingor ordinary sheet glass being overlapped with the first multiple glazingwith a gap relative thereto and having the periphery thereof sealed witha sealing material, said gap being charged with dry air or rare gas; alow-radiating film formed on either one or both of an opposing innerface of the second vacuum multiple glazing or the ordinary sheet glassopposing the first vacuum multiple glazing and an opposing inner face ofthe first vacuum multiple glazing opposing the second vacuum multipleglazing or the ordinary sheet glass.
 2. The heat-insulating multipleglazing according to claim 1, wherein said low-radiating film has aheat-through ratio not exceeding 1 kcal/m² hr° C.
 3. The heat-insulatingmultiple glazing according to claim 1, wherein said gap within saidfirst vacuum multiple glazing is depressurized to be 10⁻³ Torr or lower.4. The heat-insulating multiple glazing according to claim 2, whereinsaid gap within said first vacuum multiple glazing is depressurized tobe 10⁻³ Torr or lower.
 5. The heat-insulating multiple glazing accordingto claim 1, wherein said gap between the first vacuum multiple glazingand the second vacuum multiple glazing or the ordinary sheet glass isfrom 6 to 20 mm.
 6. The heat-insulating multiple glazing according toclaim 2, wherein said gap between the first vacuum multiple glazing andthe second vacuum multiple glazing or the ordinary sheet glass is from 6to 20 mm.
 7. The heat-insulating multiple glazing according to claim 3,wherein said gap between the first vacuum multiple glazing and thesecond vacuum multiple glazing or the ordinary sheet glass is from 6 to20 mm.
 8. The heat-insulating multiple glazing according to claim 4,wherein said gap between the first vacuum multiple glazing and thesecond vacuum multiple glazing or the ordinary sheet glass is from 6 to20 mm.
 9. The heat-insulating multiple glazing according to claim 1,wherein said sealing material includes a primary sealing material and asecondary sealing material, the primary sealing material beingisobutylene-isoprene rubber, the secondary sealing material beingsulphide sealant or silicone sealant.
 10. The heat-insulating multipleglazing according to claim 2, wherein said sealing material includes aprimary sealing material and a secondary sealing material, the primarysealing material being isobutylene-isoprene rubber, the secondarysealing material being sulphide sealant or silicone sealant.
 11. Theheat-insulating multiple glazing according to claim 3, wherein saidsealing material includes a primary sealing material and a secondarysealing material, the primary sealing material beingisobutylene-isoprene rubber, the secondary sealing material beingsulphide sealant or silicone sealant.
 12. The heat-insulating multipleglazing according to claim 5, wherein said sealing material includes aprimary sealing material and a secondary scaling material, the primarysealing material being isobutylene-isoprene rubber, the secondarysealing material being sulphide sealant or silicone sealant.
 13. Theheat-insulating multiple glazing according to claim 1 wherein the firstand second vacuum multiple glazings respectively have a thickness ofabout 6 mm.
 14. The heat-insulating multiple glazing according to claim2 wherein the first and second vacuum multiple glazings respectivelyhave a thickness of about 6 mm.
 15. The heat-insulating multiple glazingaccording to claim 3 wherein the first and second vacuum multipleglazings respectively have a thickness of about 6 mm.
 16. Theheat-insulating multiple glazing according to claim 5 wherein the firstand second vacuum multiple glazings respectively have a thickness ofabout 6 mm.
 17. The heat-insulating multiple glazing according to claim9 wherein the first and second vacuum multiple glazings respectivelyhave a thickness of about 6 mm.
 18. The heat-insulating multiple glazingaccording to claim 10 wherein the first and second vacuum multipleglazings respectively have a thickness of about 6 mm.
 19. Theheat-insulating multiple glazing according to claim 1 wherein each saidsheet glass has a thickness of less than or equal to 1.5 mm and thespacers are disposed with a pitch not greater than 15 mm.
 20. Theheat-insulating multiple glazing according to claim 2 wherein each saidsheet glass has a thickness of less than or equal to 1.5 mm and thespacers are disposed with a pitch not greater than 15 mm.